Thin aspect lighting system with cutoff

ABSTRACT

A thin aspect lighting system and method are shown. The system and method include at least one module having a reflector that is generally elliptical in one cross-section and generally parabolic in another cross-section. Each module is adapted to generate at least one of a flat beam pattern, a high beam pattern or a low beam pattern, such as a low beam pattern with a kink or elbow. Also shown is a headlamp assembly having a plurality of modules that generate the same or a different light beam pattern. Manipulation and variation of facets or positions of various components, such as at least one light source provides improved characteristics in one or more of the light beam patterns.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/849,065 filed Apr. 15, 2020 (US 2020/0355338), which is acontinuation of U.S. application Ser. No. 15/316,738 filed Dec. 6, 2016(U.S. Pat. No. 10,697,607)), which is a U.S. National Phase Applicationof International Application No. PCT/US2015/034439 (WO 2015/034439)filed Jun. 5, 2015, which claims the benefit of U.S. ProvisionalApplication No. 62/009,324 filed Jun. 8, 2014, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND Field of the Invention

This invention relates to lighting systems, and more particularly, to athin aspect forward lighting system with cutoff.

Description of the Related Art

At present, there are two large families of head-lights. A first family,those of headlights herein called “of the parabolic type”, comprisesheadlights whose beam is mainly generated by a source of smalldimensions mounted in a mirror which projects the rays onto the road inorder to form the desired beam. The window of the headlight is involved,if necessary, by being fitted with prisms, striations, and the like, inorder to model the beam, and in particular, in order to spread itwidthwise. In this case, this family includes the headlights called“free-surface” or else “Surface Complexe” (registered trademark)headlights, having the ability of directly generating a beam delimitedby a desired upper cut-off line.

These headlights have the properties of being able to generate beams ofexcellent quality in terms of light distribution, and of being, ingeneral, not very deep. How-ever, in order to generate a sufficientlyintense beam, it is necessary that their mirror or reflector recovers asignificant proportion of the light flux emitted by the lamp.

A first approach to doing this consists in using a very small initialfocal length, especially in order to obtain a mirror which is very closearound the source and of small size widthwise. However, in this case,because of the large size of the images of the source generated by themirror, the beam has in general an excessive thickness, and is in anycase difficult to control.

A second approach to recovering the light flux while obtaining a thinnerbeam consists, on the contrary, in increasing the initial focal length,but in this case the mirror must have relatively large dimensionstransversely to the optical axis, which is counter to the objective of acompact headlight.

A second family is that of headlights “of the elliptical type”. Suchheadlights are characterized by a lamp mounted in a mirror whichgenerates, with the reflected rays, a concentrated spot (typically, thesource is at the first focus of a mirror in the shape of an ellipsoid ofrevolution and the spot is formed at the second focus of the mirror),and this spot is projected onto the road by a convergent lens, usually apiano-convex lens. If the beam has to comprise a cut-off line, thelatter is produced by partly occluding the light spot where it isformed.

This second family of headlights has the advantage of being able torecover a significant proportion of the light flux emitted by thesource, while having small dimensions transversely to the optical axis.On the other hand, the photometry of the beam may prove to be difficultto model, since by nature no correcting element of the prism or striatedtype can in general correct the light downstream of the lens;furthermore, these headlights have a large size depthwise.

Furthermore, in practice, these two families of headlights have verydifferent external appearances.

Thus, the headlights of the parabolic type have a window with arelatively large width (while throughout the years, for reasons of styleand aerodynamics, their height has gradually reduced). This window isstriated or, in more recent styles, virtually smooth such that, when theheadlight is extinguished, the mirror and various types of trims areobserved perfectly on the inside.

In contrast, a headlight of the elliptical type, when it isextinguished, in general reveals only the outer convex face of the lens,which is often surrounded with a suitable trim, through a smooth window.

Nowadays, there are ever more demanding requests from designers relatingto the appearance of illuminating headlights for vehicles.

Thus certain style “trends” favor headlights of parabolic type, or ofelliptical type, or even a combination or use of both types.

Moreover, on a more technical level, there is a strong demand forheadlights having a size which is moderate not only transversely to theoptical axis, but also depthwise, that is to say along the optical axis,which, in principle, neither of the two families of headlights mentionedabove is able to obtain without making concessions in terms of qualityof illumination.

One solution of the prior art is found in U.S. Pat. Nos. 7,980,742;7,168,836 and 6,811,289. The lens width is wider than requested by acustomer and requires a diverging lens solution. The formation of a kinkor elbow in the beam pattern is not demonstrated.

The following are some additional problems with prior art designs:

Conventional lens systems cannot be adapted to customer styling for thinlens elements.

Conventional lens systems (imaging/projection lens systems) have colordispersion that may be objectionable when driving or must be managed inthe design using more complex lenses.

Conventional lens systems require more complex molding.

The invention herein overcomes one or more of the problems of the priorart.

SUMMARY

One embodiment of the present disclosure features an external light fora vehicle, comprising: a) a reflector which has (i) generally parabolicsections in side view and (ii) generally elliptical sections in topview, and (iii) a focus; b) at least one light source, part of which iscoincident with the focus, and which projects light which the reflectorreflects to form a focused line; c) a converging lens, non-parallel withthe focused line, which transmits light from the focused lineexternally, to form a beam having at least one cut-off. In all theembodiments being described, it should be understood that the lightsource may be any suitable light source, such as a light-emitting diode(LED), a non-solid state light source or a solid state light source,such as a laser LED.

As is known to one skilled in the art, the cut-off is a defined line ofcut-off below which light from the head-lamp assembly is projected. Ingeneral, the light output is below the cut-off which is below the eyesof a driver in an oncoming vehicle. As is known, the cut-off forEuropean countries is typically stepped or has a kink or elbow tofacilitate illuminating a side of the road where road signs andpedestrians are and lower oncoming traffic. In the United States, such apronounced kink or elbow is not a regulatory requirement.

This embodiment shown and described herein could be used alone ortogether and/or in combination with one or more of the features coveredby one or more of the claims set forth herein, including but not limitedto one or more of the following features or steps:

The external light for a vehicle in which intensity in at least onecut-off drops by at least 50 percent within 10 degrees of beam width.

The external light for a vehicle in which the at least one light sourcecomprises one or more light emitting diodes.

The external light for a vehicle in which the converging lens forms partof an external surface of the vehicle.

The external light for a vehicle in which the converging lens is exposedto external weathering along with external surfaces of the vehicle.

In another embodiment, an external light for a vehicle, comprising a) areflector which has (i) generally parabolic sections in side view, (ii)generally elliptical sections in top view, and (iii) a focus; b) atleast one light source comprising a light emitting diode, LED, part ofwhich is coincident with the focus, and which projects light which thereflector reflects to form a focused line; and c) an elongated lens,which (1) has neutral power along its length, (2) has a relativelynarrow aspect ratio, and (3) which transmits light received from thefocused line to form a beam having a relatively wide aspect ratio, andhaving left and right cut-offs.

This embodiment shown and described herein could be used alone ortogether and/or in combination with one or more of the features coveredby one or more of the claims set forth herein, including but not limitedto one or more of the following features or steps:

The external light for a vehicle in which the elongated lens is notparallel with the focused line.

The external light for a vehicle in which light intensity in thecut-offs drops by 50 percent within 10 degrees of beam width.

The external light for a vehicle in which the elongated lens is closerto the focused line at one end of the lens, compared with the other end.

The external light for a vehicle in which the reflector comprisessegments.

In still another embodiment, a light device for a vehicle is providedand it comprises a) at least one light source; b) a reflector whichreceives light from the light source and focuses the light to form aline in space; and c) a lens which receives light from the line, andprojects it forward of the vehicle.

In yet another embodiment, a lighting module for a vehicle is showncomprising a) a first light source which transmits light to a firstreflector, which focuses the light along a first line in space; b) asecond light source which transmits light to a second reflector, havingdifferent geometry than the first reflector, which focuses the lightalong a second line in space; c) a lens which i) receives light from thefirst line and projects the light in a first intensity pattern, and ii)receives light from the second line and projects the light in a secondintensity pattern, different from the first.

This embodiment shown and described herein could be used alone ortogether and/or in combination with one or more of the features coveredby one or more of the claims set forth herein, including but not limitedto one or more of the following features or steps:

The lighting module for a vehicle in which the first reflector comprisesparabolic sections in side view and elliptical sections in top view.

The lighting module for a vehicle in which the second reflectorcomprises parabolic sections in side view and elliptical sections in topview.

The lighting module for a vehicle in which the first intensity patternhas left and right cut-offs, and the second intensify pattern has leftand right cut-offs, which are different from those of the firstintensity pattern.

The lighting module for a vehicle in which the lens is elongated, andgenerally non-parallel with the first line.

Another embodiment comprises a lighting device for a vehicle, comprisinga reflector which is generally parabolic in a first section, generallyelliptical in a second section and has a focus, at least one lightsource which projects light to the reflector which the reflectorreflects to form a line of focus, and a lens which transmits light fromthe line of focus to form a beam having at least one cut-off.

As used herein, a line of focus refers to a combined reflection of lightfrom the elliptical cross-section and the parabolic cross-section toproduce a line of focused light LF as illustrated in the Figures, suchas FIG. 6.

Another embodiment comprises a lighting device for a vehicle, comprisinga first light source which transmits light to a first reflector, whichfocuses light along a first line of focus in space, a second lightsource which transmits light to a second reflector, having differentgeometry than the first reflector, which focuses light along a secondline of focus in space, a lens which i) receives light from the firstline of focus and projects the light in a first intensity pattern, andii) receives light from the second line of focus and projects the lightin a second intensity pattern, different from the first.

In another aspect, one embodiment comprises a lighting device for avehicle comprising a reflector which is elliptical in a firstcross-section and parabolic in a second cross-section that issubstantially perpendicular to the first cross-section and having anoptical axis defined therein, and at least one light source whichprojects light toward the reflector along a projection axis whichdeviates between 5 and 20 degrees from an optical axis, and a diverginglens which collects light received from the reflector and diffracts thelight into a less converging beam.

In still another aspect, one embodiment comprises a lighting device fora vehicle comprising a reflector having a surface which is elliptical ina first cross-section and parabolic in a second cross-section that issubstantially perpendicular to the first cross-section, the reflectorhaving a plurality of reflective facets, each positioned along ageometric surface of the reflector, such that fewer than all surfacenormals of the plurality of reflective facets are aligned with surfacenormals of the geometric surface at the respective locations of theplurality of reflective facets, at least one light-emitting diode (LED)which projects light to the plurality of reflective facets, and a lenswhich collects light from the plurality of reflective facets andcollimates the light. In this regard, it is known that a surface normalrefers to a surface at a point that is perpendicular to a plane.

In still another aspect, one embodiment comprises a lighting device foruse on a vehicle; the lighting device comprising at least one modulecomprising a reflector that is generally elliptical in a firstcross-section and generally parabolic in a second cross-section that isgenerally perpendicular to the first cross-section, the reflectorreceiving light from at least one light source and directing it toprovide a line of focused light, and a lens that is situated inoperative relationship with the reflector and the line of focused lightin order to generate a desired light beam.

In still another aspect, one embodiment comprises a lighting device foruse on a vehicle, the lighting device comprising a plurality of modules,each comprising a reflector that is generally elliptical in a firstcross-section and generally parabolic in a second cross-section that isgenerally perpendicular to the first cross-section, the reflectorreceiving light from at least one light source and directing it toprovide a line of focused light, and a lens that is situated inoperative relationship with the reflector and the line of focus, each ofthe plurality of modules generating a light beam pattern, and the lightbeam pattern from the plurality of modules cooperate to generate acomposite beam pattern.

This invention, including all embodiments shown and described herein,could be used alone or together and/or in combination with one or moreof the features covered by one or more of the following list offeatures:

The lighting device wherein the lens is tilted off a vertical planetoward the reflector by 20 degrees or less.

The lighting device wherein the at least one light source comprises oneor more light emitting diodes.

The lighting device wherein the lens comprises a side that forms part ofan external surface of the vehicle.

The lighting device wherein the lens is at least one of either divergentor convergent.

The lighting device wherein the line of focus is between the reflectorand the lens.

The lighting device wherein the line of focus is outside the lens.

The lighting device wherein the lens has a length that is greater than alength of the reflector such that a ratio of lens length to reflectorlength is greater than or equal to 1.

The lighting device wherein the lens has a width that is greater than awidth of the lens such that a ratio of reflector width to lens width isgreater than or equal to 1.

The lighting device wherein the at least one light source is rotatedrelative to a focus of the reflector in at least one of a vertical planeor a horizontal plane.

The lighting device wherein the at least one light source is rotated inonly in a horizontal plane to provide a kink in the beam.

The lighting device wherein the lens has a thin aspect and is generallynarrow along its length.

The lighting device wherein the lens is closer to the line of focus atone end of the lens compared with the other end.

The lighting device wherein the reflector comprises a plurality ofsegments or facets.

The lighting device wherein at least one of the plurality of segments orfacets is aimed or deviated from an optical axis of the reflector or isdefocused. As is known in the art, with a parabolic reflector, light ata focus of the parabola will be collimated and reflected to infinitygenerally parallel to the optical axis. With “defocused” light, such asby moving the at least one light source relative to the focus, lightrays go to another focus in space either up, down or sideways relativeto the optical axis of the reflector. Thus, by defocusing, the imagefrom the at least one light source can be directed to provide a portionof the overall light beam pattern. In the illustration being described,the at least one light source is defocused to provide the kink or elbowdescribed herein. As explained later herein, a manipulation of one ormore portions of the reflector can also facilitate providing uniquecharacteristics to the beam pattern, such as the kink or elbow justmentioned.

The lighting device wherein the lens is inclined relative to thereflector. In this regard, the lens may comprise a longitudinal axisthat may be inclined relative to the reflector such that a first end ofthe lens is closer to the reflector than a second end of the lens. Ifthe axis of the lens is generally vertical, for example, then the axiswould be inclined or tilted away from vertical at an angle. In theillustrations being described, the angle of inclination is typicallyless than 20 degrees (20°) and in some embodiments approximately tendegrees (10°).

The lighting device wherein the first section is a horizontal sectionand the second section is a vertical section.

The lighting device wherein the first reflector comprises parabolicsections in side view or vertical section and elliptical in top view orhorizontal section.

The lighting device wherein the second reflector comprises parabolicsections in side view or vertical section and elliptical in top view orhorizontal section.

The lighting device wherein the first intensity pattern has left andright cut-offs and the second intensity pattern has left and rightcut-offs, which are different from those of the first intensity pattern.

The lighting device wherein the lens is elongated and is generallynon-parallel with at least one of the first line of focus or the secondline of focus.

The lighting device wherein the first intensity pattern comprises akink, whereas the second intensity pattern does not.

The lighting device wherein the diverging lens diffracts the light intoa beam containing parallel rays.

The lighting device wherein the at least one light source comprises atleast one light-emitting diode (LED) and the projection axis of the atleast one light source lies in a horizontal plane.

The lighting device wherein the projection axis of the at least onelight source is deviated from the optical axis of the reflector by 5 to15 degrees.

The lighting device wherein the plurality of reflective facetscollectively have an optical axis and the at least one light-emittingdiode (LED) has a projection axis which deviates from the optical axishorizontally by 5 to 20 degrees.

The lighting device wherein the at least one light source is at leastone of an LED or a solid state device.

The lighting device wherein the line of focused light is between thereflector and the lens.

The lighting device wherein the line of focused light is outside anexternal surface of the lens and not between the lens and the reflector.

The lighting device wherein the lens is a divergent lens and the atleast one module generates at least one of a flat beam pattern, a highbeam pattern or a low beam pattern.

The lighting device wherein the lens is a convergent lens and the atleast one module at least one of a flat beam pattern, a high beampattern or a low beam pattern.

The lighting device wherein the reflector has a plurality of facets, atleast one of which is configured and dimensioned to generate apredetermined characteristic in the light beam.

The lighting device wherein the predetermined characteristic comprises akink or elbow.

The lighting device wherein the at least one light source is deviated orangled in at least one plane to cause the light beam to be defocused orto have a predetermined feature.

The lighting device wherein the at least one light source is deviated orangled in a horizontal plane that is generally parallel to an opticalaxis of the reflector and the predetermined feature is a kink or elbow.

The lighting device wherein the light beam is at least one of a flatbeam pattern, a high beam pattern, a beam pattern having a kink or elbowor a low beam pattern that conforms to SAE or ECE beam patternrequirements.

The lighting device wherein the first cross-section is taken in ahorizontal plane and the second cross-section is taken in a verticalplane.

The lighting device wherein the at least one module is at least one of alow beam module, a high beam module or a flat beam module.

The lighting device wherein the lighting device comprises at least onesecond module, the at least one module and the at least one secondmodule generating different beam patterns.

The lighting device wherein the at least one module generates a flatbeam and the at least one second module generates a low beam.

The lighting device wherein the low beam comprises a kink or elbow.

The lighting device wherein the lighting device comprises at least onethird module that generates a third beam that is different from thebeams generated by the at least one first module and the at least onesecond module.

The lighting device wherein the plurality of modules each utilize thesame lens but separate reflectors.

The lighting device wherein the plurality of modules comprises a firstmodule that generates a first beam pattern and at least one secondmodule that generates a second beam pattern, the first and second beampatterns being the same.

The lighting device wherein the plurality of modules comprises a firstmodule that generates a first beam pattern and at least one secondmodule that generates a second beam pattern, the first and second beampatterns being different.

The lighting device wherein the lenses for the plurality of modules areintegral and continuous.

The lighting device wherein the first module is a flat module and thefirst beam pattern is a flat beam pattern, the at least one secondmodule is a low beam module and the second beam pattern is a low beampattern the composite beam pattern including both the flat beam patternand the low beam pattern.

The lighting device wherein a common lens is used for both the firstmodule and the at least one second module.

The lighting device wherein low beam pattern comprises a kink or elbow.

The lighting device wherein the reflector of the at least one secondmodule comprises a plurality of facets, the kink being generated byadapting a shape or direction of at least one of the facets.

The lighting device wherein the kink being generated by angling aposition of the at least one light source relative to a focus of thereflector of the at least one second module.

The lighting device wherein the plurality of modules comprise at leastone high beam module for generating a high beam, at least one flat beammodule for generating a flat beam, and at least one low beam module forgenerating a low beam, the plurality of modules being adapted to beenergized simultaneously or independently to generate the compositebeam.

The lighting device wherein the plurality of modules are stacked.

These and other objects and advantages of the invention will be apparentfrom the following description, the accompanying drawings and theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a generalized representation of one formof the invention, showing (1) a reflector R, which is elliptical inhorizontal cross-section and parabolic in vertical cross-section, (2) ageneralized lens L, and (3) a light emitting diode LED;

FIG. 2 illustrates an ellipse, showing how light originating at focus F2will be reflected to focus F1;

FIG. 3 illustrates a truncated ellipse ET and again showing how lightoriginating at focus F2 will be reflected to focus F1;

FIG. 4 shows a light source positioned at focus F2 of the truncatedellipse ET;

FIG. 5 shows how light originating at a focus FP of a parabola P(FIG. 1) is reflected as parallel rays R;

FIG. 6 illustrates how light transmitted by an light source is reflectedby the reflector R to a line of focused light, called a line focuslabeled LF;

FIG. 7 shows that the line focus LF need not be linear;

FIG. 8 shows the line focus LF located between the lens L and thereflector R, and illustrates one cross-sectional shape of the lens L ofFIG. 1;

FIG. 9 shows the line focus LF located beyond the lens L, andillustrates another cross-sectional shape of the lens L;

FIG. 10 illustrates a reference vertical plane PV;

FIG. 11 is a top view of FIG. 10;

FIG. 12 is a side view of FIG. 10;

FIG. 13 illustrates the light source located at the focus F2 of thetruncated ellipse ET of FIGS. 1 and 3;

FIGS. 14, 15, 16, and 17 illustrate the light source displaced forward,aft, right and left of the focus F2, respectively;

FIGS. 18 and 19 show the light source displaced and/or at an anglerelative to the major axis of the truncated ellipse, but located at thefocus F2;

FIGS. 20-27 illustrate the light source displaced from an ellipticalfocus and a parabolic focus, and in some views angled relative to anoptical axis of the reflector.

FIG. 28 is a view of a light module in accordance with one embodimentfor producing a flat beam pattern;

FIGS. 28A-28C are light beam intensity plots or pictures showing thebeam generated by the module of FIG. 28;

FIG. 29 is a view of a module in accordance with another embodiment forproducing a high beam pattern;

FIG. 29A is a light beam intensity plot for the light beam shown in FIG.29;

FIG. 30 is a module in accordance with another embodiment for producinga low beam pattern;

FIG. 30A is a light beam intensity plot and associated picture for theembodiment shown in FIG. 30;

FIGS. 31A-31B are alternative embodiments of the module shown in FIG.30;

FIGS. 32A-32F are views of another embodiment showing the reflector witha plurality of facets;

FIG. 33A-33C are intensity beam plots showing a kink produced using anembodiment where the at least one light source position is angledrelative to a focus of the reflector;

FIG. 34 illustrates another embodiment utilizing a converging lens andwherein a focused line is between the converging lens and the reflector;

FIG. 35 is an intensity plot diagram for the embodiment shown in FIG.34;

FIG. 36 is a test picture and associated intensity beam picture showinga light beam with kink;

FIGS. 37A-37D are views illustrating various light beam intensitypatterns;

FIGS. 38A-38D and 39A-39B illustrate various embodiments wherein aplurality of modules are combined, such as in a stacked configuration,and used with a single lens;

FIGS. 39C-39E are various light intensity plots for the embodimentsshown in FIGS. 39A and 39B;

FIG. 40 is a schematic diagram illustrating two high beam modules in astacked configuration but without any housing or bezel assembly for easeof illustration;

FIG. 41 is a light beam intensity plot for the embodiment shown in FIG.40;

FIGS. 41A-41G illustrate how the lens L can be shaped to present anexternal contour which is conformal with the external surface of avehicle;

FIG. 42 illustrates how the lens L can also act as a waveguide to carryan additional light beam;

FIGS. 43-46 illustrate different embodiments of the invention;

FIGS. 47-49 illustrate an ellipse constructed of individual facets, andhow the facets can collectively form a light beam of desiredcross-sectional shape; and

FIG. 50 is a plan view of various modules and assemblies illustrating aheadlamp assembly adapted and shaped to a contour of the vehicle.

DETAILED DESCRIPTION

The invention improves over various prior art devices, including thoseshown in U.S. Pat. No. 7,980,742, to Albou, issued Jul. 19, 2011; U.S.Pat. No. 7,121,705 to Albou, issued October, 2006; U.S. Pat. No.7,390,112, to Leleve, issued June, 2008; and U.S. Pat. No. 7,524,095, toAlbou, issued April 2009, all of which are incorporated herein byreference and made a part hereof.

The invention concerns a “thin aspect” headlight or other lightingand/or signaling devices, hereinafter collectively referred to as alighting device, for vehicles. The “aspect” in “thin aspect” refers to“aspect ratio,” which is the ratio of height H to width W, or H/W. Thus,a thin aspect ratio refers to a headlight which is tall and narrow.However, despite the fact that the thin aspect light is tall and narrow,the lighting device provides a beam pattern that conforms to SAE and/orECE standards. The beam is typically short and wide. That is, a thinaspect lighting device, which is tall and narrow, generally produces atypical beam which has a wide aspect and is short and wide light beam.In the illustrative embodiments, the aspect ratio of lens height toreflector width is greater than or equal to 1. Also, the ratio ofreflector width to lens width is also greater than or equal to 1.

Another feature of the embodiments being described is that the thinaspect light utilizes a lens, such as a cylindrical lens, divergent orconvergent lens, which can have an outer surface that is adapted orshaped to follow a contour or surface of the vehicle for stylingpurposes and aerodynamic benefits.

In general, the lighting device of the embodiments described hereinprovides a main headlamp beam, such as a high beam, a low beam or a lowbeam with kink or an elbow. In other embodiments described later, thelighting device allows light to be guided or passed through the lens ata direction that is generally cross or transverse to the main beam toprovide a secondary lighting function, such as a daytime running light(DRL), turn signal, park light or the like. Some general principles ofoperation of the invention will now be described to facilitateunderstanding of the various features of the invention.

FIG. 1 is a simplified diagram of one form of the invention. At leastone light source projects light to a reflector R, which reflects thelight to a lens L, shown as a block for ease of illustrating basicprinciples of the invention. In all the embodiments being described, itshould be understood that the at least one light source may be anysuitable light source, such as a light-emitting diode (LED), a non-solidstate light source or a solid state light source, such as a laser LED.As will be understood from the description below, the lens L may be, forexample, a convergent lens or a divergent lens. The lens L focuses thelight into a beam of appropriate cross-sectional shape to be shownlater.

The reflector R is constructed with a specific shape. In a horizontalplane or cross-section PH, the shape is elliptical as shown. In avertical plane or cross-section PV, the shape is parabolic as shown. Theelliptical cross-section exploits a specific characteristic of anellipse and the parabolic cross-section exploits specificcharacteristics of a parabola. In this regard and as shown in FIG. 2,the ellipse E has a first focus F1 and a second focus F2. A light rayoriginating at focus F2 of the ellipse E will always be reflected to itsother focus F1, no matter in what direction the ray travels away fromthe originating focus F2. This reflective property is present, even ifthe ellipse is truncated into the truncated ellipse ET in FIG. 3.Therefore, as in FIG. 4, light originating from a light source locatedat focus F2 will be focused to the second focus F1.

The parabolic cross-section in plane PV exploits a specificcharacteristic of the parabola, namely, that light originating at thefocus FP of a parabola will be reflected as parallel rays. FIG. 5illustrates this characteristic. If the light source is located at thefocus FP, then rays R will be parallel after reflection.

FIG. 6 illustrates the combined reflections. The result is that a linefocus of light, labeled LF in FIG. 6, is generated. In actuality, theline focus LF will generally follow a shape of the parabolic verticalcross-section PV, as indicated in FIG. 7. However, if the paraboliccross-section is rather flat, then for practical purposes, the linefocus LF can be viewed as a straight line, as in FIG. 6.

As will be described and shown later herein if the line focus LF ispositioned between the reflector R and the lens L, as in FIG. 8, then aconverging lens L can be used to collimate the light. If the line focusis positioned outside the lens L, as in FIG. 9, then a diverging lens Lcan be used to collimate the light. These features will be describedlater herein.

The pattern of the beam produced in FIGS. 8 and 9 will depend on thegeometries and relative positions of (1) the light source, (2) thereflector R, and (3) the lens L. FIG. 1 shows the vertical referenceplane PV and the associated parabolic shape (FIG. 5). The cross-sectionin the horizontal plane PH shows the cross-section of the reflector Rand its truncated ellipse ET (FIGS. 3 and 10). FIG. 10 is a plan or topview in the horizontal plane PH; and FIG. 11 is a cross-section or sideview in the vertical plane PV, showing the parabolic cross-section(labeled PAR in FIG. 11).

FIGS. 12-19 are plan views, similar to FIGS. 4 and 10. In FIGS. 12-19, Xand Y axes are superimposed in the horizontal plane with an origin beinglocated at the elliptical focus F2. In FIG. 12, a forward direction,FWD, is defined, and is the forward direction of a vehicle V (FIG. 41F)on which the lighting device 10 is mounted. An aft direction, AFT isalso shown, which is the opposite of the forward direction. Left andright directions are indicated in FIG. 12 as well.

For ease of illustration, the at least one light source is shown as anLED, but it should be understood that it could be any type of lightsource, such as an LED, laser LED or other conventional light source.FIG. 12 shows the light source positioned at the focus F2 of the ellipseET. However, the light source need not be positioned there. FIG. 13shows the light source positioned forward of the focus F2, that is, inthe negative X direction, and FIG. 14 shows a light source positionedaft of the focus F2, that is, in the positive X direction. FIG. 15 showsthe light source positioned to the right of the focus F2, that is, inthe positive Y direction. FIG. 16 shows the light source positioned tothe left of the focus F2, that is, in the negative Y direction.

FIG. 17 shows a general case where the light source is displaced in boththe X and Y directions, and either positively or negatively in eachdirection. In the example of FIG. 17, the light source is displaced inthe negative X direction and in the positive Y direction.

In addition, the direction of the light projected by the light sourceneed not coincide with the optical axis of the system, which is taken asthe X-axis in this case. As FIG. 18 shows, the projected light can beoff-axis from the optical axis of the reflector R, which is the X-axis,and FIG. 19 illustrates the general case. The light source can bedisplaced from the focus F2, and the projected light (which follows theoptical axis of the light source) need not be parallel to the opticalaxis, namely, the X-axis.

These same principles apply to the positioning of the light source withrespect to the parabolic focus FP (FIG. 5) of the paraboliccross-sections. For example, FIG. 5 shows the light source positioned atthe focus FP of the parabola. However, as just stated, the light sourcecan be positioned to the left, right, above, or below the focus FP andit can be tilted or rotated with respect to it. Thus, as explained inconnection with FIGS. 18 and 19, a direction of the projected light canbe adjusted, although this fact perhaps only has relevance when thelight source is displaced from the focus FP of the parabola because ifthe light source is located at the focus FP, then all light willnecessarily be reflected as parallel rays by the parabola.

The Inventors have found that the displacements of the light source fromthe foci just discussed and rotation of the light source will alter thebeam patterns produced. Further, it has been found that certaincombinations of displacements produce alterations which are veryfavorable in a vehicle headlight. When these features are used with thereflector R and lens L described herein, an improved light beam isgenerated as described herein. However, it is not practical to attemptto manually analyze a beam pattern which will be produced by a givenapparatus in FIG. 1, with given displacements of the light source. Aprimary reason is that the reflective properties of an ellipse, when theat least one light source is not located at a focus, are extremelycomplex. Therefore, as a practical matter, computer modeling has beenused.

Positioning of Elliptical and Parabolic Foci and the Light Source

FIG. 1 is a perspective view with the horizontal reference plane PH andthe vertical reference plane PV superimposed as mentioned. FIG. 20 is across-sectional or plan view taken through the horizontal referenceplane PH of the ellipse of FIG. 1. The light source is located in thisplane. FIG. 21 is a cross-sectional side view in the plane PV of theparabola of FIG. 1.

FIG. 22 indicates that the focus FE of the ellipse of FIG. 1 iscoincident with the focus FP of the parabola shown in FIG. 1 and FIG. 5.However, it is possible that those foci need not coincide and they canbe offset from each other both vertically and horizontally. In someembodiments, separation of the two foci provide a favorable or desiredbeam pattern as described herein. FIG. 23 indicates a deviation in the Ydirection, labeled DEL Y, and a deviation in the X direction, labeledDEL X. Each deviation can be positive or negative. In a preferredembodiment, the light source is deviated plus or minus only along theoptical axis (X) and is generally not shifted in the Y-axis laterally.FIG. 26 indicates a deviation in the Z-direction, labeled DEL Z, whichcan be positive or negative. It is noted that the ellipse focus FE isthat of the ellipse in the horizontal plane which contains the lightsource. In addition, the light source can be angled or rotated withrespect to the foci FE and FP, as indicated by angle A in FIGS. 24 and27. The light source can also be displaced from the focus FE, asindicated by DEL Y and DEL X in FIG. 27.

Now that the general features and principles of operation of theinvention have been described, several embodiments will now bedescribed. As will be seen, several lighting device modules have beendeveloped using these principles and these modules generate differentbeam patterns. The modules can be used alone or together, such as in astacked configuration shown and described later herein.

FIGS. 28-31B illustrate several embodiments or modules 10, 12 and 14that produce different or unique lighting patterns. In the embodiment ofFIG. 28, a lighting device or module 10 provides a forward lightingautomotive module that utilizes a thin aspect lens 18 for styling. Forease of understanding, the embodiments of FIGS. 28-31B are illustratedwithout the supporting housing, bezel or structure which will bedescribed later herein. Thus, it should be understood that thecomponents of the various modules illustrated in FIGS. 28-31B aremounted in or to a suitable housing, bezel or support structure andsituated on a vehicle, such as the vehicle V illustrated in FIG. 41F.Also, for ease of illustration, the modules are shown in a side view anda plan view as indicated.

In the illustration being described, the module 10 in FIG. 28 generatesa generally flat beam pattern shown and described later herein, and themodule 12 (FIG. 29) generates a high beam pattern. The module 14 inFIGS. 30-31B generates a low beam pattern having a kink. As mentioned,these modules 10-14 can be used alone or in combination, such as in astacked form, as shown and described later herein. The modules 10-14 areunder the control of a controller (not shown) and can be energizedindependently or simultaneously. Thus, the modules 10-14 can be usedseparately or together to provide different beam patterns, such as, ahigh beam pattern or a low beam pattern with cut-off that conform to thelight pattern designs prescribed by the Society of Automotive Engineers(SAE) in the United States and the Economic Commission for Europe (ECE).

For ease of understanding, several beam intensity plots are shown anddescribed herein. The axes of the plots shown in the figures arecalibrated in angular units with respect to the lens, but in principal,the plots indicate how the beam would appear if projected onto a flatwall. The SAE and ECE plots for the embodiments being described possesstwo significant features. One is that there is a rather sharp cut-off onthe left and right sides. A second is that there is an intensely brightcentral region. The particular intensity pattern produced by the variousmodules and the reflector/lens combinations described herein depend onthe geometries of the materials and components used and a combination ofone or more of the features mentioned earlier and other factors.

Referring back to FIG. 28, the flat beam module 10 is shown. In thisembodiment, the module 10 comprises a divergent lens 18 having a lensfocus that is coincident with a line of focus LF. Note in theillustration, that the lens 18 is tilted off vertical (as viewed in FIG.28) approximately ten degrees (10.degree.), but the tilt could begreater or less depending on the beam pattern desired. Preferably, thetilt is less than twenty degrees (20.degree.).

In the embodiment of FIG. 28, the module 10 also comprises a reflector20 which is elliptical in cross-section in the horizontal plane PHdescribed earlier herein relative to FIG. 1 and parabolic in thevertical plane PV described earlier. In the illustration beingdescribed, the reflector 20 has a smooth reflective surface 20 a in oneembodiment, but it could be faceted as described later herein. The lens18 is shown as being smooth on a first side 18 a and on a second side 18b. However, the second side 18 b could have one or more modulations orother optics to, for example, increase a spread of the light beam and/orprotect its homogeneity. In this example, the first side 18 a iscontinuous and smooth which makes it advantageous when mounted on thevehicle V because it can match a contour C and a surface S (FIG. 41F) ofthe vehicle V, thereby presenting various styling options.

As alluded to earlier, the reflector 20 has an interior surface 20 athat is reflective. The reflector 20 can me made conventionally using athermoset or thermoplastic material that can be metalized with areflective coating and the like. One feature of the illustrations beingdescribed is that the reflectors, such as the reflector 20 in theembodiment of FIG. 28, whether they are faceted or not, have anelliptical cross-section in the horizontal plane PH and parabolic in thevertical plane PV that collect source light and direct it to produce aline focus LF.

In the embodiment of FIG. 28, the reflector 20 has a focal length of theparabola of approximately 8-9 mm. A light source 24 is situatedsubstantially at the parabolic and elliptical focus and cooperates withthe reflector 20 to generate a line focus LF at approximately 33 mm infront of the second surface 18 b of the lens 18. Note that the reflector20 is approximately 40 mm wide while the lens 18 b is approximately 30mm wide. Thus, the reflector 20 is wider than the lens 18 by a ratiogreater than or equal to 1. Note also that the reflector 20 has a heightof approximately 40 mm, and the height of the lens 18 is greater thanthat of the reflector 20, and the ratio of lens 18 length to reflector20 length is greater than or equal to 1. In one embodiment, the ratio ofthe reflector 20 width to the lens 18 width is greater than 40 mm/10 mm.

It is important to note that the reflector 20 and light source 24generate the line focus LF that is between the lens 18 and reflector 20.The divergent lens 18 receives and collimates the light to generate agenerally flat beam plot and associated image shown in FIG. 28A.

FIG. 28B illustrates another embodiment showing the lens 18 generallycurved or arcuate along its longitudinal length which illustrates thatthe side 18 a of the lens 18 may be styled to match, for example, thestyling or body shape of the vehicle V. Note that the cut-off can bemade flat with the tipped lens 18. Note that the lens 18 is tipped orinclined in the side view illustrated and curved in the plan view. Inone embodiment, the lens 18 is tipped or inclined at an angle of lessthan twenty degrees (20.degree.).

As mentioned, the flat module 10 in FIG. 28 produces an intensityprofile plot (FIG. 28A) that is wide and flat as shown by the plot andpicture in FIG. 28A. It is flat in the sense that a single intensity ofmedial value is spread out through nearly all the beam. It is wide inthe sense that it spans thirty to forty degrees (30.degree.-40.degree.)both left and right, which is approximately sixty to eighty degrees(60.degree.-80.degree.) total span in the illustration being described.The intensity profile plot for the alternative embodiment of FIG. 28B isshown in FIG. 28C. Note that the flat intensity profiles indicate a widebeam that is generally lacking in a central region of high intensitywhen compared to other embodiments described herein. The pattern of FIG.28A shows a spread of plus or minus 35 degrees with about 57% efficiencyof light output to light input from the light source 24. The beam showsa flatter cut-off, redistribution of light from a center of the patternand an increase in vertical spread of about 1-2 degrees.

Referring now to FIG. 29, another embodiment of the invention is shownillustrating the module 12 for generating a high beam. This embodimentalso comprises a reflector 32, which may be smooth or faceted asdescribed later herein, a lens 34 and at least one light source 36.Again, the at least one light source can be any suitable source, such asone or more conventional LEDs or laser LEDs. Unlike the embodimentdescribed relative to FIG. 28, note that this embodiment comprises aconvergent lens having a width of approximately 33 mm as shown and adepth of approximately 10 mm. Like the embodiment shown in FIG. 28 forthe flat module 10, note that the lens 34 is tilted or inclined offvertical approximately ten degrees (10.degree.) as shown. In theillustration being described, the reflector 32 generates a line focus LFbetween the lens 34 and reflector 32 that is approximately 25 mm infront of the surface 34 b. As with the embodiment of FIG. 28, thesurface 34 a of the lens 34 may be curved along its longitudinal lengthand in cross-section as shown in order to generally conform to thecontour or shape of the contour C (FIG. 41F) of the surface S of thevehicle V.

It should be understood that like the embodiment described relative toFIG. 28, note that the lens 34 is a converging lens that is tall andnarrow and not as wide as the reflector 32. Its aspect ratio is greaterthan or equal to 1. This is further illustrated in the bottom rightportion of FIG. 29. The lens 34, therefore, has a length that is greaterthan a length of the reflector 32 as shown. In the illustration beingdescribed, the lens 34 is approximately 30-40 mm longer than thelongitudinal length of the reflector 32 which is on the order of about40 mm in length. It should be understood that like the prior embodiment,the reflector 32 is elliptical in the horizontal cross-section or planePH and parabolic in the vertical cross-section or plane PV.

The associated high beam intensity plot for module 14 is illustrated inFIG. 29A and shows a narrowed and more intense beam compared with theother light intensity plots described herein. Note the central region ofgenerally high intensity, as shown in FIG. 29A.

FIG. 30 illustrates still another embodiment showing the module 14 forgenerating a beam pattern that comprises a kink or elbow as required bythe ECE. In this embodiment, the module 14 comprises a lens 42, areflector 44 and at least one light source, which is again is shown asan LED for ease of understanding. In this embodiment, the light source42 is divergent and is tilted off vertical toward the reflector 44. Thelens 42 has a length of approximately 50 mm, while a length of thereflector 44 is less, so that the aspect ratio of lens 42 height toreflector 44 height is greater than or equal to 1. The ratio ofreflector 44 width to lens 42 width is greater than or equal to 1. Thelens length or height is greater than or equal to the reflector height.It has been found that the 80 mm height is only for styling. The factthat the lens 42 has an extruded cross-section allows the height to betaller than a normal imaging lens. In the illustration, the reflector 44has a parabolic focus of approximately 13-15 mm at which the lightsource 46 is situated as shown. It is important to note that the linefocus LF is not between the lens 42 and the reflector 44, but rather, isin front of the front surface 42 a of the lens 42 as shown. In theillustration being described, the line focus LF is approximately 30 mmin front of the surface 42 a of the lens 42. Note that the light source46 is situated approximately 90 mm from the surface 42 a of the lens 42.In an alternate embodiment described later herein relative to FIGS.31A-31B, note that this distance could be between 110-140 mm. Note thatthe light source 46 is rotated 15 degrees in the side view. A distancebetween a rear surface 44 a and the surface 42 a is on the order ofabout 108 mm, and in the alternate embodiment, between 90-120 mm. In thealternate embodiment, the overall length of the reflector 44 may bebetween 30-60 mm. As with the other embodiments, note that the reflector44 is elliptical in the horizontal plane PH and parabolic in thevertical plane PV as mentioned earlier.

It should be understood that the dimensions and relative relationshipsmentioned for all embodiments may change depending on the size of thereflector 44.

FIG. 30A illustrates the intensity profile plot and associated picturefor the module 14.

FIGS. 32A-32D illustrate another embodiment of the module 14 wherein thereflector 44 comprises a surface 44 a having a plurality of facets 44 c.As mentioned earlier, the reflectors 20, 32 and 44 could also have oneor more facets 44 c. The features of various facets 44 c will bedescribed later herein, but it should be understood that the facets 44 cgenerally conform to the elliptical and parabolic shape of the reflector44. As explained later, the facet shape, position and dimension may bechanged or altered to optimize the beam pattern, such as providing apattern having an elbow or kink (labeled 44 g in FIG. 33A), which isconventionally referred to as an ECE kink.

In the illustration being described, the reflector 44 (FIG. 32C)comprises twelve regions of facets, with each region comprising nineindividual facets 44 c. The light images produced by the facets 44 ccooperate to generate the light pattern as described in more detaillater. In this embodiment, the facets 44 c of regions 44 d-44 f aremodified to provide the kink or elbow 44 g illustrated in the lightintensity associated with the embodiment of FIG. 32C which isillustrated in FIG. 33A. It should be understood, therefore, that onefeature of the invention is that the facets 44 c that make up one ormore regions 44 d-44 f of the reflector 44 may be modified to optimizethe beam pattern to have a desired shape or to provide specific featuressuch as a kink or elbow in the pattern. As illustrated in FIGS. 32D-32F,all or portions of the facet 44 c can be aimed or deviated from theoptical axis up or down and laterally (Y) to position the light. Thisallows the facet 44 c to become “defocused” and the orientation of theat least one light source will provide the desired kink or elbow in thepattern.

For example, with a parabolic reflector, light at a focus of theparabola will be collimated and reflected to infinity generally parallelto the optical axis. With “defocused” light, such as by moving the atleast one light source relative to the focus, light rays go to anotherfocus in space either up, down or sideways relative to the optical axisof the reflector. Thus, by defocusing, the image from the at least onelight source can be directed to provide a portion of the overall lightbeam pattern. In the illustration being described, the at least onelight source is defocused to provide the kink or elbow described herein.As explained later herein, a manipulation of one or more portions of thereflector can also facilitate providing unique characteristics to thebeam pattern, such as the kink or elbow just mentioned.

FIG. 32D shows the facet 44 c aimed or deviated. FIG. 32E shows aportion of the facet 44 c aimed or deviated. FIG. 32F shows a portion ofthe facet 44 c truncated or repositioned.

The inventors have found that another way to modify the light beamintensity profile and to improve the formation of kink steps, such asthe kink 44 g shown in the plot of FIG. 33A, is to rotate the lightsource 46 or change its position in a manner described earlier herein.For example, the light source 46 could be rotated vertically (FIG. 31A)and/or horizontally or in the horizontal plane PH (FIG. 31B). Thus, inthis embodiment of FIG. 31A, the module 14 is shown as having the lightsource 46 angled downward by an angle of approximately five to fifteendegrees (5.degree.-15.degree.) as shown in FIG. 31A. The angle .beta. ismeasured between the flat base of the light source 46 and the horizontalas indicated in FIG. 31A. When the five to fifteen degrees(5.degree.-15.degree.) deviation or pivot is imposed, then the opticalaxis of the light source 46 will also be rotated toward the reflector 44the same number of degrees, namely five to fifteen degrees(5.degree.-15.degree.), respectively, in this example. In theillustration being described, this rotation increases the collection oflight by portions of the reflector 44, such as the facets 44 c in theregions 44 d-44 f of the reflector 44.

Note in the embodiment of FIG. 31B, the light source 46 is rotated inthe horizontal plane PH as shown. In this illustration, the light source46 is rotated approximately five to twenty degrees(5.degree.-20.degree.). It has been found that rotating or pivoting thelight source 46 in the manner shown in FIGS. 31A and 31B improves thecut-off of the light beam or an abrupt drop in the light intensity atthe edge of the beam as illustrated in FIG. 30A.

As mentioned earlier, it should be understood that the dimensions areillustrative, and other dimensions may be used, which will depend on theenvironment the lighting device is used.

In the embodiment of FIGS. 30-31B, the line focus LF is positionedforward of the lens 42 and is not between the reflector 44 and the lens42.

Further, the alternate side view indicates that the optical axis of thelight source 46 is angled downward at an angle .beta. by 5 to 15degrees, as indicated. The angle .beta. is measured between the flatbase of the light source and the vertical as indicated in FIG. 31A. Whenthe 5 to 15 degree deviation is imposed, then the optical axis will berotated toward the reflector 44 by that same 5 to 15 degrees. Thisrotation increases collection of light in desired areas of the reflector44.

Further still, the alternate plan view (shown in the bottom portion ofFIG. 31B) indicates that the optical axis of the light source 46 isrotated away from the optical axis of the reflector R by 5 to 20degrees. It has been found that this improves the cut-off of the beam.It should be noted that a cut-off in the light pattern is an abruptdrop-off in brightness at the edge of the beam as illustrated.

FIG. 33A illustrates the light intensity when the light source 46 isrotated approximately fifteen degrees (15.degree.) in the horizontalplane PH illustrated in FIG. 31B. FIG. 33C shows the same embodiment ofFIGS. 30-31B with the light source 46 rotated downward only slightly(approximately one degree) (1.degree.). FIG. 33B illustrates the lightsource 46 rotated both in the vertical plane PV and horizontal plane PHshown in FIGS. 31A and 31B, respectively. In the illustration of FIGS.33A and 33C, the light source 46 was a 450 lumen source.

The following Table I summarizes various characteristics or dimensionsfor these illustrative embodiments:

TABLE 1 Flat Model High Beam Kink SAE Kink 2 ECE (FIG. 28) (FIG. 29)(FIG. 30) (FIGS. 31A-31B) Reflector Height (H) 40 mm 40 mm <50 mm or30-60 mm <50 mm or 30-60 mm Width (W) 40 mm 40 mm  50 mm or 40-60 mm  50mm or 40-60 mm Lens Divergent Convergent Divergent Divergent Height(H) >40 mm >40 mm  50 mm or 30-80 mm  50 mm or 30-80 mm Width (W) 30 mm30 mm Depth (D) 10 mm 10 mm 10 mm 10 mm Focal Distance 8-9 mm 8-9 mm13-15 mm 13-15 mm Lens Tilt =10° =10° =10° =10° Light source None None15° vertically or 5-15° 5-15° in horizontal Rotation in vertical and/orplane PH and 5-20° horizontal plane in vertical plane PV

FIG. 33B shows the intensity plot for the embodiment of FIGS. 30-31Bwhere a 500 lumen light source 46 was rotated approximately fifteendegrees (15.degree.) in both the horizontal plane PH and the verticalplane PV. This embodiment is particularly adapted to create a headlampdevice that generates a beam pattern that complies with SAE standards.In this embodiment, the light source 46 is rotated fifteen degrees(15.degree.) in the vertical plane PV. The light intensity plot is shownin FIG. 34. Note the difference in the intensity plots of FIG. 33A,where the light source 46 was rotated in the horizontal plane PHapproximately fifteen degrees (15.degree.), which generated the kink. Incomparison, the light source 46 was not rotated in the horizontal planePH in the SAE embodiment of FIG. 35, but was rotated in the verticalplane PV, which generated a distinct cut-off, but not the ECE kink. Thispattern conforms to SAE standards.

FIGS. 34 and 35 illustrate another embodiment of showing the module 50that generates an SAE conforming pattern. In this embodiment, the module50 comprises a converging lens 52, reflector 54 and light source 56 thatgenerates the line focus LF between the lens 52 and reflector 54 asshown. The resultant isolux pattern is shown in FIG. 35 having afavorable cut-off and no kink. In this embodiment, the light source 56was rotated in the vertical plane PV approximately fifteen degrees(15.degree.).

A test device 51 for the module 14 is shown in FIG. 36. The device 51has a housing 53 that receives and supports the reflector 44 and thelens 42. A top support 53 a of the housing 53 receives and supports thelight source 46. This embodiment generates the patterns mentionedearlier relative to FIGS. 33A-33C, for example.

The embodiments shown and described relative to FIGS. 29-34 illustratevarious modules for generating a high beam, flat beam, SAE kink and alow beam as well. For ease of comparison, the high beam, flat beam, SAEkink beam and ECE kink beam are shown in FIGS. 37A-37D.

Advantageously, the inventors have found that a wide variation of thinaspect beam patterns can be generated using the embodiments describedherein. A common characteristic of each embodiment is that the reflectoris elliptical in the horizontal plane PH and parabolic in the verticalplane PV. The various facets of the reflectors, such as reflector 44,can be adapted or modified to enhance the aspects of the various lightbeam patterns, such as enhancing the cut-off, kink or elbow. Theinventors have also found that by manipulating the position of the lightsource and/or using different combinations of a divergent or convergentlens with the reflector can produce preferred results. The control ofthe dimensions of the reflector and the light source position alsofacilitates eliminating the need to use a folder or traditional imaginglens.

The lens width dimension for each embodiment provides a thin aspect ofthe width relative to the length which can be very advantageous forstyling purposes when the lighting device is mounted on the vehicle V.While the various lenses may be contoured and may have microstructure toimprove diffusion of light, the necessity for such features is reducedor eliminated. Note that this occurs in one integrated optical system ordevice which can use a single lens or multiple lenses. Again, the lensesof the embodiments being described can be made taller than traditionalimaging lenses without creating a thick, molded part. The shape of thelenses also allows the light source and reflector parts to be rotatedindependently from the lens, allowing cut-offs and kinks to be achievedwhile using a fixed lens. Again, the optical system allows the outerside of the lens to be defined by the contour C (FIG. 41F) and stylingof the vehicle V, thereby allowing consistency in appearance betweendifferent lenses or multiple reflectors behind the single lens.

The reflector and the inside surface of the lens may be manipulated ordesigned to control the light beam pattern, as opposed to changing theshape or characteristics of the lens itself. The shape of the lensallows the lens to be integrated as an external lens, such as beside,adjacent to or integral with the surface of the vehicle, which allowsfor reduced parts and costs and provides for unique stylingopportunities.

While each of the embodiments have been shown using a single lightsource or monochip, it should be appreciated that the at least one lightsource could comprise multiple chips or multiple light sources, such asconventional LED or laser LED or other types of light sources. Themodules 10, 12 and 14 shown in FIGS. 28-31B are adapted and capable ofbeing used alone or together such as in a stacked composite arrangementof the type shown in FIGS. 38A-38D to provide a headlamp assembly 60. Ingeneral, FIGS. 38A-38D illustrate the headlamp assembly 60 comprising alens 62 and a plurality of reflectors 64 that are mounted to a bezel 68.Note that a light source 66 is associated with each of the reflectors64. The bezel 68 has a bottom member 70 and a top member 72. The bezel68 further comprises a back wall or member 74 having a plurality of stepsurfaces 74 a-74 e. The reflectors 64 are mounted on the steppedsurfaces 74 a-74 e between the bottom member 70 and top member 72 andconventionally fixed or secured to the step surfaces 74 a-74 e. Notethat in the illustration being described, the bezel 68 does not have anyside walls so that the ends, such as end 64 a and 64 b of reflectors 64may extend through the open sides 68 a and 68 b, respectively, of thebezel 68, as illustrated in FIGS. 38B and 38C. Note how the reflectors64 are generally wider than the lens 62 which has a relatively thinnerwidth, thereby facilitating providing and defining the thin aspect ofthe headlamp assembly 60. It should also be noted that a single lens 62can be used with multiple reflectors.

Advantageously, the modules 10-14 may comprise a single type of module,such as the flat beam, high beam or kink beam modules 10, 12 and 14shown in FIGS. 28-31B. Alternatively, different modules may be combinedor assembled together to provide a headlamp assembly 60 having a desiredbeam pattern. For example, in FIG. 39A, an embodiment is shown utilizinga plurality of the modules. For ease of illustration, the embodiment isshown schematically with the reflectors 20, 44 and 64 being integralwith a support 88 which would either be part of or mounted to a bezel(not shown). In this illustrative embodiment of FIG. 39A, three flatmodules 10 are combined with a kink module 14 to provide a low beamheadlamp assembly. Advantageously, a single divergent lens 62 is usedwith all reflectors that has an associated light source 24 or 46 asshown. Just as with the description of the modules earlier, it should beunderstood that the reflectors are parabolic in the vertical plane PVand elliptical in the horizontal plane PH. It should be understood thatthe modules 10, 12 and 14 are independently actuable and energizable toprovide one or more desired beam patterns. FIG. 39C illustrates a lightintensity plot for the embodiment of FIG. 39A. The embodiment of FIG.39A produces a composite low beam SAE headlamp assembly 60.

FIG. 39B shows another embodiment showing two flat modules 10, a highbeam module 12 and a kink module 14 with the single divergent lens 62 ina stacked arrangement. In this embodiment, the kink module 14 utilizes a500 lumen light source 46, whereas the flat modules 10 utilize a 450lumen light source. The light intensity diagram for this embodiment isillustrated in FIG. 39C.

It should be understood that the various light sources 46 are under thecontrol of the controller (not shown) that independently and/orsimultaneously energizes the various modules 10-14 to create the desiredlight pattern.

FIG. 39E illustrates a comparison of a high beam simulation of the thinaspect headlamp shown in FIG. 39B. The bottom isolux plot shows a mockup using a 450 lumen light source. FIG. 39E shows the simulated andmeasured isolux plots for the composite low beam module 60 utilizing asimulated headlamp assembly and an actual mockup of the type describedearlier.

FIG. 40 is a schematic illustration of a composite high beam modulecomprising a combination of two stacked high beam modules 12. In theillustration, both modules can be independently energized. Thus, in FIG.40, the composite high beam headlamp 90 is shown having a lens 34, aplurality of reflectors 32 and light sources 36, which are 450 lumenLEDs in the example. The modules 14 function and operate in the samemanner as the modules described earlier herein relative to FIG. 29. Theassociated light intensity plot for the composite high beam module 90 isshown in FIG. 41.

Additional Features and Considerations

1. FIG. 41F shows a reflector R reflecting rays 70 which form a sheet oflight in a single plane. FIG. 41B shows a similar sheet of rays 72, butat a different position. FIGS. 41C and 41D indicate the sub-planes 74and 76 within the lens L. FIG. 41E indicates how the lens L can bedivided into two sections L1 and L2. This concept is applied in FIGS.41F and 41G.

FIG. 41F indicates the contour C of the surface S of the vehicle V. LensL is designed to be conformal with the body. In FIG. 41G, the lens L isdivided into blocks L1, L2 . . . LN, which are arranged to provide thecontour C of FIG. 41F. In effect, a large number of very thin layers L1,L2 in FIG. 41E are stacked as in FIG. 41G to form the desired externalshape of the lens L. As mentioned earlier, the lens could be aone-piece, integral construction used for all modules 10-14, oralternately separate lenses may be stacked as shown.

2. FIG. 42 illustrates another embodiment in which a light source 80launches an additional light beam 82 into the lens 84, in addition tothe main beam or beams (not shown) from light sources 88 reflected tothe lens 84 by the reflectors 86. One or more of these modules 10-14could be used in this embodiment. The beam 82 is reflected by reflector90 to perform a secondary function, such as a DRL, side light orsignaling function, as when the beam 82 acts as a turn signal. In thisembodiment, the beam 82 is generally transverse to the main beamreflected by reflectors 86. Alternately, the end of the lens 84 can beequipped with optics, such as frosting F, to diffract the beam 82, toprovide a glowing region at the location of the frosting. The inventorspoint out that the lens 84 in this situation performs a dual function:it focuses light received from reflectors 86 to provide a main beam or abeam that performs a first function and it acts as a waveguide for lightreceived from the light source 80 to provide a second beam that performsa second function.

3. In some instances, it may be desired to defocus the beam. FIGS. 43and 44 illustrate an embodiment for doing so. As the top view indicates,a light source 100 is rotated so that its projection axis is notparallel with the axis of the reflector 102. Light source 100 isdisplaced from the focus F of the reflector 102, as the side viewindicates, and its projection axis is not parallel with the axis of thereflector 102. This causes a de-focalization of the beam.

4. FIG. 45 illustrates still another embodiment in which a module 110has a reflector 112 having a vertical cross-section that is elliptical,as opposed to the horizontal cross-section being elliptical as discussedabove. The reflector 112 is parabolic in the horizontal plane as shownby the plan view. A light source 116 and lens 114 are arranged as shown.FIG. 46 illustrates multiple modules 110 of the type shown in FIG. 45,wherein the vertical cross-section is elliptical. Multiple modules 110are placed adjacent each other to form a slanted composite structure asshown. Facets F of the type described earlier relative to FIGS. 32A-32Dare present in the lens 114.

5. The isolux or light intensity plots are tracings of plots which wereproduced by the commercially available optics analysis software known asASAP, available from Breault Research Organization, Inc. of Tucson,Ariz. Some basic principles used by this software are the following.

6. In some embodiments, it was mentioned that the reflector could have aplurality of facets, such as facets 44 c in FIG. 32C. FIG. 47, leftside, illustrates a single facet FC, which is a small reflector, ormirror. It has an axis AX with an imaginary reference grid G alignedwith the axis AX some distance away. The grid G contains a horizontalaxis H and vertical axis V.

The facet reflects light emitted by a source (not shown), and thereflected light forms an image IM. The position of the image on the gridG will depend on the orientation of the facet FC with respect to theaxis AX. It can also depend on the shape of the facet FC, that is, onwhether the facet FC is convex, concave or a more complex shape.

Recall that the reflector, such as reflector 44 shown in FIGS. 32A-3Ccomprises a plurality of segments, such as segments 44 d-44 f, and eachof these segments 44 d-44 f comprise a plurality of facets. In thisillustration, the segments comprise nine facets. However, it should beappreciated that the reflector R could be divided into more or fewersegments and the segments can have more or fewer facets. FIG. 48, showsnine facets FC, formed into a reflector analogous to the reflector 44 inFIG. 32B. Each facet FC in FIG. 48 forms its own image IM, on areference grid GG, and some images IM can overlap, as indicated at thelower right region of the combined grids G. The collected images IM formthe projected beam or light intensity profile or plot. In theillustration shown in FIG. 48, the beam pattern relates to a low beampattern with kink, and the image, labeled IMK in FIG. 48 forms at leasta portion of the kink described earlier herein. The images IM from allthe segments and facets are combined to create the low beam intensityprofile. The same is true for the other beam intensity profiles, such asthe profiles for the flat beam and the high beam described earlier. Inother words, each facet creates an image from the light it receives fromthe at least one light source and the collective images are compositedto create the beam pattern. In FIG. 48 the reference grid GG shows thenine sections A-I, each having an X and Y axis as shown. The grids areshown in a projected view for ease of understanding which image comesfrom each facet. In reality, the images from each of the facets, A-I,are overlaid on top of each other (as illustrated in the bottom righthand portion of FIG. 48) to generate the beam pattern.

A significant feature is that the facets FC are positioned and/ordimensioned independently, as opposed to uniformly. For instance,Example 1 in FIG. 49 indicates uniform positioning. The facets arealigned with an ellipse E. Each facet FC has a similar characteristic.For example, one edge of each facet FC can form a chord of the ellipseE. That is, corner points PL and PK of the facet would lie on theellipse. Thus, one or more facets FC could be parallel to a tangent tothe ellipse at the facet's midpoint MP. In Example 1, all facets areuniformly positioned and configured with respect to the ellipse E.

In contrast, in Example 2, each facet FC is positioned and configuredindependently. The positioning is determined by the desired location ofthe image IM in the collective grid GG to be produced by the facet FC.Given that independence, the uniformity of Example 1 will be absent.Specifically, in Example 2, all facets will not form chords of theellipse, although some may do so. Similarly, in Example 2, all facetswill not be parallel with tangents located at the midpoint of a facet.

This discussion considered the horizontal cross-sections, which areellipses. These principles apply to the vertical cross-sections, whichcan be parabolic. The facets are independently positioned with respectto the parabola. Thus, the facets can comprise different shapes andsizes and will contribute to produce aspects of the beam pattern, suchas the kink or elbow mentioned earlier.

A reflector containing such independently positioned and facets can beconstructed of an injection molded substrate of plastic resin, and thencoated with a reflective coating.

Advantageously, the controlled manipulation of the facets of eachreflector permit the resultant beam to have desired characteristics,such as a sharp cut-off or distinct kink (as described earlier hereinrelative to FIG. 32C).

7. As mentioned earlier herein, one advantageous feature of theembodiment being described is its ability to meet styling demands andprovide a lens that complements the contour C of the vehicle V. Thefeatures described herein permit a cut-off to be formed exclusively bythe reflector, thereby allowing the lens design to be less complex. FIG.50 illustrates four illustrative designs 90, 92, 94 and 96 showingdifferent shapes and sizes of the headlamp assemblies that may bemounted on the vehicle V which may comprise one or more of the opticalmodules 10-14 described herein. Note how the assembly can take uniqueand different elongated shapes and provide a tall thin aspect.

Also, note that the assembly of modules 90-94 each comprise a housing 90a, 92 a, 94 a that supports the internal components of one or more ofthe modules 10-14. The lens 90 b and 94 b of modules 90 and 94,respectively, are smooth on both sides, while an inside surface 92 b 1is modulated to provide desired diffusion.

Finally, once mounted on the vehicle V, the lens conforms to the contourC of the vehicle V, thereby providing numerous styling opportunities.Thus, unique styling opportunities are available with the use of asingle lens and multiple modules. This is illustrated with the headlampassembly 96.

A brief summary and other general observations, features and advantagesare as follows:

The designs provide a forward lighting automotive module 10 thatutilizes a thin aspect (low width) lens for styling. The device canproduce a LB module with cutoff (ECE or SAE), or Flat, or HB beampatterns. The optical concept is comprised of a light source, complexreflector (metalized), and a cylindrical type lens (extrudedcross-section). In general, the reflector forms a line image at thefocus of the lens. The device can be used with other modules withidentical front faces for a homogeneous look for styling. Advantagesinclude more simplified molding and manufacture than comparativealternatives, and the designs do not have color dispersion common tomany lens solutions.

In one form of the invention, multiple light sources are provided, eachassociated with (1) a respective reflector of the parabolic/ellipticaltype, and (2) a projection lens. These modules are stacked in a tall,narrow column, and produce a short, wide light beam to provide a thinaspect low beam. They can also be arranged horizontally. A key point isthat their aspect ratio of height/width of the lens to the reflector isgreater than or equal to one degree (1.degree.). Multiple lenses couldbe used for multiple reflectors, respectively, or a single lens may beused with all reflectors.

A converging lens solution is achieved that has advantages for stylingand the possibility of additional functionality.

The at least one light source can be any suitable light source, such asa LED light source monochip, a multichip, such as a 1.times.2 multichipor combination thereof.

A faceted, non-imaging reflector can be used to collect source light anddirect to a line focus. The design of the reflector forms the cutoff ofthe beam pattern. The reflector is freeform with facets dedicated toforming an ECE or SAE type cut-off. Also Flat and HB patterns can beformed.

The reflector can be made of standard methods:thermoset+varnish+metallization, or thermoplastic and metallizationmetal.

A cylindrical concave or cylindrical convex lens can be used with focusat the line focus of the reflector. For a divergent lens, the focus isvirtual outside the device and for a converging lens, the focus ininside the device. In general, the lens has an extruded cross-section,made of plastic or glass.

The various cylindrical lenses 18, 32 and 42 have an A-side (visibleside) matching the styling intent. The A-side lens surface does not haveto be aspherical based on optical considerations.

The device is used in combination with other modules to form a low beampattern. For example, it may include one kink module and one flatmodule. Other combinations are possible.

The following features or advantages of various embodiments of theinvention may be used alone or in combination:

An optical system that is comprised of reflector and lens. The reflectorbe generally parabolic in side view, and elliptical in plan view. Thereflector can form a line focus before or after the lens. The lens canhave extruded imaging cross-section in plan view and be neutral in sideview.

An optical system where the reflector controls the cut-off formationwithout use of a folder and traditional imaging lens.

An optical system that reduces the lens width dimension (thin aspect)versus traditional imaging lenses.

A reflector that uses complex facets to optimize the beam pattern. Thisallows kinks with steps (ECE kink), sign light to be created.

The use of a rotated light source that improves the formation of kinksteps.

An optical system that does not produce color dispersion like a typicalimaging system, which is better for an end user and eliminates the needfor microstructure to diffuse light.

The shape allows multiple modules to be integrated into a design usingone common lens (drawing). The shape of the lens allows the lens to bemade taller than a traditional imaging lens without creating a thickmolded part.

The shape of the lens allows the at least one light source and reflectorparts to be rotated independently from the lens, allowing cut-offs to beaimed while using a fixed lens.

The optical system allows the lens A side to be defined by styling,allowing consistent appearance between different lenses or multiplereflectors behind a single lens. The reflector and lens B side, which isthe side opposite the A side, are changed to control the light pattern,as shown in FIG. 50.

A shape of the lens allows the lens to be integrated as an externallens, such as a side in outside environment as shown in FIG. 41F. Thisallows reduced parts, reduced cost and unique styling.

A lens with extruded cross-section that allows light to be guided orpassed through the lens, at a cross direction from the main beam(optical axis as shown in FIG. 42). This could allow the lens to be usedfor a second function (park, turn, position, or DRL).

An optical system that allows the use of multiple light sources, somelight sources in a defocalized location (FIGS. 43 and 44) that allow ashift in beam pattern from LB state to HB state.

Meet styling demands for unique styling with narrow lens elements andtall aspect.

Simplify the lens molding with less complex lens, and more tolerance(versus comparable alternatives).

A lighting system capable of meeting styling desire for a tall, thinaspect lens with a surface defined by styling.

A system cut-off formed exclusively by the reflector, allowing lensdesign to be less complex.

This invention, including all embodiments shown and described herein,could be used alone or together and/or in combination with one or moreof the features or steps mentioned in the Summary of the Invention andcovered by the claims, both of which are incorporated herein byreference.

While the system, apparatus and method herein described constitutepreferred embodiments of this invention, it is to be understood that theinvention is not limited to this precise system, apparatus and method,and that changes may be made therein without departing from the scope ofthe invention which is defined in the appended claims.

What is claimed is:
 1. A lighting device of a vehicle, comprising: areflector that is generally parabolic in a first section and generallyelliptical in a second section; at least one light source, a portion ofwhich is coincident with a focus, said light source projects light tosaid reflector from which a focused line is formed; and a lens thattransmits light from said focused line that is configured to form a beamusing at least one cut-off; wherein said light source comprises a numberof light emitting diodes (LED) or solid state lights; wherein said lenshas a length in comparison to a length of said reflector of a ratio, alens length to reflector length ratio, greater than or equal to 1;wherein said reflector has a width in comparison to a width of said lensof a ratio, a reflector width to lens width ratio, greater than or equalto 1; wherein said lens has a thin aspect ratio and is generally narrowalong its length; and wherein said lens is closer to said focused lineat one end than as compared with the other end.
 2. The lighting deviceaccording to claim 1, wherein said lens is tilted off a vertical planetoward said reflector by 20 degrees or less.
 3. The lighting deviceaccording to claim 1, wherein said lens comprises a side that forms partof an external surface of the vehicle.
 4. The lighting device accordingto claim 1, wherein said focused line is between said reflector and saidlens.
 5. The lighting device according to claim 1, wherein said focusedline is outside said lens.
 6. The lighting device according to claim 1,wherein said at least one light source is rotated relative to at leastone focus of said reflector in at least one of a vertical plane or ahorizontal plane.
 7. The lighting device according to claim 1, whereinsaid lens is an elongated lens that has a neutral power along a lengthof said elongated lens.
 8. The lighting device according to claim 7,wherein said elongated lens is not parallel with said focused line. 9.The lighting device according to claim 1, wherein said reflectorcomprises a plurality of segments or facets.
 10. The lighting deviceaccording to claim 9, wherein at least one of said plurality of segmentsor facets is aimed or deviated from an optical axis of said reflector oris defocused.
 11. The lighting device according to claim 1, wherein saidfirst section is a horizontal section and said second section is avertical section.
 12. The lighting device according to claim 1, whereinsaid lens is inclined relative to the reflector.
 13. The lighting deviceaccording to claim 1, wherein a projection axis of said at least onelight source is deviated from said optical axis of said reflector by 5to 15 degrees.
 14. The lighting device according to claim 1, wherein:said reflector has a plurality of reflective facets, each positionedalong a geometric surface of said reflector, such that fewer than allsurface normals of said plurality of reflective facets are aligned withsurface normals of said geometric surface at the respective locations ofsaid plurality of reflective facets; said at least one light sourcewhich projects light to said plurality of reflective facets; and saidplurality of reflective facets collectively have an optical axis andsaid at least one light source has projection axis which deviates fromsaid optical axis horizontally by 5 to 20 degrees.
 15. The lightingdevice according to claim 1, wherein said reflector has a plurality offacets, at least one of which is configured and dimensioned to generatea predetermined light beam characteristic; and wherein said light beamcharacteristic is at least one of a flat beam pattern, a high beampattern, a beam pattern having a kink or elbow or a low beam patternthat conforms to Society of Automotive Engineers (SAE) or EconomicCommission Europe (ECE) beam pattern requirements.
 16. A modularlighting device applied on a vehicle, comprising: a plurality of moduleseach comprising the lighting device according to claim 1, wherein eachof said plurality of modules generates a light beam pattern, and saidlight beam patterns from said plurality of modules cooperate to generatea composite beam pattern; and wherein said plurality of modules arestacked.
 17. The lighting device as recited in claim 16, wherein saidplurality of modules each utilize the same lens but separate reflectors.18. The lighting device as recited in claim 16, wherein said lenses forsaid plurality of modules are integral and continuous.
 19. The lightingdevice as recited in claim 16, wherein a common lens is used for both afirst module of the plurality of modules and a second module of theplurality of modules.
 20. The lighting device as recited in claim 17,wherein said plurality of modules comprises at least one high beammodule for generating a high beam, at least one flat beam module forgenerating a flat beam, and at least one low beam module for generatinga low beam, said plurality of modules being adapted to be energizedsimultaneously or independently to generate said composite beam.